Piezoelectric devices provide very efficient transfer of energy. As such, these devices can be used to provide very efficient conversions devices such as for DC--DC converters, power transformers, and the like. However, the power handling capability of piezoelectric devices is limited. Therefore, applications requiring higher power levels require correspondingly larger piezoelectric devices. Such devices would occupy a substantial amount of space on a printed circuit board, much more so than other electronic components used in the specific power conversion circuit. In addition, it is desirable to provide packaging to protect the piezoelectric device from the environment, even for non-hermetic applications such as in power conversion devices. This additional packaging further increases the space needed to mount the piezoelectric device in the circuit.
Typically, piezoelectric packaging consists of a metal or a ceramic. Not only do these packaging schemes add substantial size to the piezoelectric device, they also add considerable cost to the piezoelectric device. In particular, non-standard or large packages can cost more than the piezoelectric portion of the device itself. Moreover, metal packaging can be a distinct disadvantage in high voltage applications as arcing can occur between the regions of the piezoelectric resonator that are at high potentials and the metal package.
There is a need for a piezoelectric resonator that would take up minimal or zero space on top of a printed circuit board. In addition, it would be desirable to provide as large a piezoelectric resonator as needed for a specific power conversion circuit application without penalty of circuit board space or total overall circuit height. Further, it would be advantageous to isolate regions of the piezoelectric resonator that are at high potentials to prevent high voltage discharges to other portions of the specific circuit. Moreover, it would be beneficial to provide a packaged piezoelectric resonator that adds minimal cost to a power conversion circuit.